Electro-photographic printers comprise a photo imaging plate and a charge roller. A background voltage is applied to the photo imaging plate by passing the charge roller across its surface. A light source, such as a laser is shone on selected areas of the photo imaging plate to substantially discharge the selected areas and create a latent electrostatic image on a charged background. When an electrostatic ink is applied to the photo imaging plate, the potential differences between the background, the image areas and the electrostatic ink are such that the electrostatic ink is drawn to the image areas of the photo imaging plate. Thus an impression of the image areas can be printed by transferring the electrostatic ink from the photo imaging plate to a print media.
This method of printing is prevalent, for example, in industrial printers capable of printing several large sheets of paper, such as B2 sized paper, per second.